Multiple control of electric motors.



R. RICHTER.

A MULTIPLE CONTROL OF ELECTRIC MOTORS.

APPLICATION FILED APR. 9, 1912.

1,080,588. Patented DQQ-9,191.3.

- mg? is a specification.

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Patented Dec. 9, 1913.

Application fled April 9, 1811. Serial Io. 889,8:80.

To all when it may concern: Be it known that I, Rononr Rlon'rnn, a subject of the German Emperor, residing at Griinau, Mark, Germany, have invented new and useful Improvements in Multiple Control of Electric Motors, of which the follow-.

or starting and regulating separately fed electric motors, for instance the motors of several motor-driven vehicles of an electric railway, from one place (multiple contended through all the carriages of electrically driven trams render the arrangement complicated and diflicult of inspection, when the control switch has a large number of switching steps, and in addition complicated auxiliary devices. are necessary or a number of separate devices, corresponding to the number of switching steps, which devices may give rise to irregularities in working. The regulation is in general not continuous but stepwise. The resent invention avoids these difiioulties. t will admit of particularly simple and effective control of separately fed electric motors by the difference between the electromotive force at the respective driving motors orcorresponding parts of the windings of these motors an an electromotive force which can be arbitrarily adjusted by the control switch being utilized to actuate a device for regulating the electromotive force to be supplied to the driving motors, which device will vary the electromotive force. at the motors until the diilerence compared to the electromotive force adjusted by the control switch is again compensated, in other" words until theelectromotive force of the driving motors or that at corresponding parts of the winding of these motors is ual to the electromotive force adjusted. n railways operated by alternating current the difierence 'in electror'notive force is made to act on the auxiliary motor, ,which drives the induction r lat-or (rotary current transformer) inten ed forregulating the electromotive force of the which are t vehicle motors. By such means it will be possible by suitably constructing the control switch, to obtain any desired number of switching steps, without more control leads having to be laid than are necessary for driving the auxiliary motors, for which purpose in general one lead will be sufiicient. The furt er advantage is also obtained, that the ressure at the drivin motors can be continuously varied instea of stepwise as with the hitherto customary control syste S.

.When the motors to be controlled are of different types corresponding winding, namely such at which the same or proportional electromotive forces occur, will not be always accessible. For example if in one of the driving motors, which may be assumed as alternating current series motors the field winding andthe working winding are connected, but separate in the other or the others, the field windings cannot be taken into consideration as winding parts in the sense of the present invention as in this case the electromotive forces would not be equal at the field windings of the several motors. These special auxiliary windings would have to beprovided in the motor, at which corresponding electromotive forces will appear. It is therefore advisable and also for this reason more simple as no tapping of the motors is required, to connect the whole electromotive force of the motor in opposition to that, adjusted by the control switch only, instead of the electromotive force of a single winding part only.

The electromotive forces must obviously relate to the same current in motors of the same power, in other words such winding parts must be taken into consideration, the

electromotive force of which is the same at formation may also sometimes be of advantage in respect to the auxiliary motors,

In motors fed from two on not directly under. the inthe rotor the secondary windings of which auxiliary transformers are connected in seferent types.

The energy is supplied to the motors through the transformers T, which again are fed from the feeder li'ne'by means of collectors The other ends of the pri mary windings p of the transformers are grounded. The leads connecting to the driving motors F or F respectively are branched off at a and b respectively to the secondary winding '5 of an lnduction regulator or rotary transformer I, which serves to regulate the electromotive force supplied to the driving motor. This is done in the known manner by turning the primary winding 2' of the induction regulator, which is connected at o and 1- to the secondary winding of the transformer T. The rotation of the induction regulator is effected by means of a transmission gearing, indicated in the drawing by the reference latter m, from an auxiliary motor H which is shown as motor having independent excitation. The field winding k connects the same as the primary winding 2' of the induction regulator to a constant voltage of the transformer ,T. The working winding h is c'on nected at one end to the switch levers of the control switch S, at the other in the diagram shown on the left hand of thedrawing to the connection 71- between the motor E and the secondary winding 2' of the induction regulator, so that at the working winding of the respective auxiliary motor H there will revail an electromotive force composed o the step voltage of the transformer corresponding to the respective position of the control switch, and the voltage at the driving motor F In the vehicle with double circuit driving motor F. according to the right hand of the drawing a voltage will be produced by the transformers t and t which is equivalent to the total .volta e of the series motor F, the primary win 'ngs of the said transformers being connected to the field winding f and the working winding f respectivel of the motor F. The common middle ead which proceeds from a point is between the primary windings connected in series, is connected at g to the point of connection of the working winding f to the field windings f of the motor F from where a compensatingv lead connects in known manner with a pomt e in the secondary windin 8 of the transformer T. From this lea is branched off at r the feeder for the primary winding 1: of the induction regulator I, the other end of which is connected the same as shown on the left hand of the drawin over n at a to the secondary winding e. ith this constructional form the end of the working winding h of the auxiliary motor H, which is not connected to the control switch S, is connected to the secondary windings of the auxiliary transformers t t connected in series to the other end of which is connected at b with the secondarv winding 8 .of the main transformer T. The contacts 1, 2 and 3 of the control switch S are connected to the tapping I points b, d and a respectively of the secondary of the main transformer. The number of these tapping points or switch contacts can of course be varied arbitrarily. Besides the switch may be replaced by an induction regulator of the kind as indicated by I, when it Is desirable to continuously vary the electromotive force at the driving motors to any intermediate step. The leads connecting the auxiliary motors H and the switch levers of the control switch S are connected with each other by a lead L.

The operation of the arrangement is as follows: The control switch which is not in use is cut out. In the drawin this is the switch of the vehicle on the rig t hand. It may now be assumed that the train is at rest and no current is supplied to the driving motors. To such a" condition corresponds a position of the induction regulator I, at which the electromotive force of the transformer T is compensated by that of the secondary windings i of the induction regulator. The lever of the control switch S on the left stands on contact 1. It is obvious, that in this case neither of the auxiliary motors H will receive any current, so that the condition remains unchanged. When new the contact lever is moved to contact 2, the circuit containing the auxiliary motor H and the driving motor F which proceeds from the point 11 of the secondary winding of the transformer T and returns over the contact 2, the working winding of the auxiliarymotor H and the point n of the driving motor F to 6, contains an electromotive force corresponding to the transformer step b-d, which as the .opposed electromotive force of the driving motor isat zero will act with its full forceon the auxiliary motor H.

iii

,the driving motor F, so that the same grocauxiliary motor H, the amount of w ich dependson the difference between the electromotive force adjusted at the switch S and.

the adually increasin electromotive force of. t e driving motor has returned to vzero. The rotation of the induction regulator, and with it the variation of the electromotive force at the driving motor then ceases so that the .electromotive'force at the driving motor reaches a value which is es-,.

sentially equal to that adjusted at the switch S. When the switch is moved on to contact 3, the just described process is repeated and the electromotive force at the driving motor reaches a value which corresponds to that adjusted at the contact 3. B such means it is possible to vary arbitrarily the electromotive .force in working b shifting the driving switch, .the number 0 steps of which is optional. In consequence of the several control switches being connected to each other by the lead L the electromotive force adjusted at the one control switch, say the left, will come also into action in the circuit of the other vehicle containing the auxiliary motor H and the corresponding winding parts (in the instance shown the-secondary side of the auxiliary transformers t, t) of ess will occur here as in the other ve icle, the control switch of which has been operated. Therefore the electromotive force of 'all driving motors is simultaneously regulated exactly to a voltage corresponding to that adjusted by the control switch on the one vehlcle.

The present invention may obviously also be app ied with other kinds of current. If direct current is employed adjustable series resistances are rovided or devices, which will effect an adjustment of the brushes for var ing the voltage.

at I claim is:

1. A system for controlling separately fed electric motors from one place, comprising driving motors, an' electric source therefor, meansfor changing the voltage impressed on said drivin motors, means controllin said first nam means, means whereby sai second named means is under the control of an arbitrarily selected voltage, and con-- nections whereby said second named means is rendered'dependent upon the electromotive force of corresponding parts of the driving motors, so that the influence on the said last named means ceases as soon as the electromotive force becomes equal to the arbit'rarilX selected voltage.

system for controlling separately fed.

electric motors from one place, comprising driving motors, an electric source therefor, means for changing the'volt'age impressed on said drivin motors, auxiliary transformers in connection with some of the driving motors, said transformers being ada ted to equalize the electromotive force of t e cor responding driving motors with that of the driving motors not connected to the transformers, means controlling said first named means, means whereby said second named means is under the control of an arbitrarily selected volta e and connections whereby said second named means is'rendered so dependent upon the electromotive force of the secondary of the said transformers that the influence on the said second named means ceases as soon as the electromotive force becomes equal to tor, a rotary additional transformer as volt- 7 age regulator for the latter, control switches and auxiliary motors for driving said rotary transformers on each locomotive, means for connecting the armature windings of said auxiliary motors to said control switches and to corresponding parts of the windings of said driving motors and means connected with said control switches for switching in different points on said main transformers.

4:. In an alternating current traction system, the combination with locomotives, each including a main transformer a driving motor, a 'rotary additional trans ormer as voltage regulator for the latter, control switches and auxiliary motors for drivingsaid rotary transformers on each locomotive, means for connecting the armature windings of said auxiliary motors to said control switches and to corresponding parts of the windings of said driving motors, means connected with said control switches for switching in different points on said main transformers and leads connecting said control switches to each other.

-5. In an alternating current traction system, the combination with locomotives, each including a main transformer, adriving motor, a rotary additional transformer as voltage regulator for the latter, control switches and auxiliary motors for driving said rotar transformers on each locomotive, the win' ings'of the driving motor and the seconda windings of the rotary transformer ofeac being inserted in a circuit, the ends of which are connected to different points of the seconda winding of the res ctive main trans ormers, a control switch aving a plurality of contact plugs on each locomotive, one of said plugs bein connected to one end of-said'circuit, the ot er one to a point of the secondary of the respective main trans former, and leads connecting the armature windings of said auxiliary motors to the re- I s ective control switches and to a point of name to this specification in the presence of t e respectiw e circuit between the windings two subscribing witnesses. of said drivmg motors and the secondaries of said rotary transformers, respectively, RUDOLF C said first named connecting leads of each Witnesses: locomotive being connected to each other. HENRY HAsrER,

In testimony whereof I have signed my WOLDEMAR HAUP'I. 

